Antibiyotiklerin anaerobik mikrobiyal komunite üzerindeki etkisinin belirlenip, metabolit oluşumu ve antibyotik direnç gelişiminin incelenmesi

Antibiotics which are one of the most commonly used pharmaceutical products have a wide range of uses in both human and veterinary medicine. These unfamiliar substances to existing enzyme systems are discharged to receiving bodies without or a little mineralization from treatment plants and accumulated in soil and sediment day by day. In this thesis, aims to develop an understanding of triple effects of sulfamethoxazole-erythromycin-tetracycline (ETS) and dual effects of sulfamethoxazole-tetracycline (ST), erythromycin-sulfamethoxazole (ES) and erythromycin-tetracycline (ET) on the microbial community structure, development of antibiotic resistance genes (ARGs), and how this relates to anaerobic sequencing batch reactors (SBRs) performance throughout a year operation. This study also evaluated understanding the link between anaerobic microbial diversity and biodegradation of antibiotic combination and the occurrence of transformation products (TPs) in anaerobic reactors by amendments of different antibiotics combination and stepwise increasing concentrations. Concentrations of the antibiotics in the influent were gradually increased until metabolic collapse of the SBRs, which corresponded to ETS (40+ 3+ 3 mg/L), ES (2.5 + 25 mg/L), ET (4+ 4 mg/L) and ST (25 + 2.5 mg/L). Although COD removal efficiency and biogas/methane generation for ETS, ES, ET and ST fed SBRs decreased with increases of antibiotic concentrations, ETS and ET batch reactor showed a better performance compared to ST and ES batch reactors; this could be due to antagonistic effects of sulfamethoxazole. Anaerobic pre-treatment of these antibiotics can be a suitable alternative for concentrations at 10 + 1 mg/L, 1 + 10 mg/L, 2 + 2 mg/L, 20 + 2 + 2 mg/L for ST, ES, ET and ETS reactor respectively which corresponds to min 70% COD removal efficiency. Antibiotic measurement and TPs formed results of this study also indicated that the anaerobic process eliminated 1 mg/L, 15 mg/L, and 0.5 mg/L for ERY, SMX and TET antibiotics respectively which corresponds to average of 80% antibiotic degradation efficiency during SBRs operation. 16S rRNA quantification and Ion Torrent result could reflect the anaerobic SBRs performance. The results of this research support the idea that molecular and metagenomic analysis could be used for providing of the control and the improvements on the anaerobic system treating pharmaceutical wastewater. Additionally, evaluation of molecular data is useful for suggesting the potential to control ultimate microbial community composition via bioagmentation to successful for antibiotic biodegradation. Overall, the results reveal a valuable information about effect of antibiotic combinations on the development of ARGs in the anaerobic SBRs, even after anaerobic treatment, contribute to the spread of these genes in aquatic environment, which may increase the risk of ARGs to public health.